Press roll gearing differential



Oct. 4, 1932. E. E. BERRY PRESS ROLL GEARING DIFFERENTIAL Filed Jan. 26, 1931 2 Sheets-Sheet l [I III Oct. 4,1932.

PRESS ROLL GEARING DIFFERENTIAL Filed Jan. 26, 1931 2 Sheets-Sheet 2 E. E. BERRY l;880,690

Patented Oct. 4 1932 UNITED STATES PATENT; OFFICE EARL E. BERRY, OF BELOIT, WISCONSIN, ASSIGNOR TO BELOIT IRON WORKS, 013 BELOIT, WISCONSIN, A CORPORATION OF WISCONSIN PRESS ROLL GEARING DIFFERENTIAL Application filed January 28, 1931. Serial No. 511,168.

This invention relates to a press roll drive and more particularly to driving mechan sm for press rolls of a paper machine includlng a differential gear, whereby the peripheral speed of'the upper and lower .press rolls may be maintained substantially the same lndependently of any change in the diameter of one of the rolls.

In the patent to Metcalf No. 1,767,088, dated June 24, 1930, there is described a press roll drive wherein this'desired result is obtained by the use of a differential gear directly connected to the lower press roll and through a train of gearing to the u per press roll. One of the disadvantages 0 thls type of driving mechanism is that as the distance between the axes of the upper and lower press rolls decreases, due to grinding down of the lower press roll, the intermeshing gears on the upper and lower press rolls no longer properly cooperate and it is necessary from time to time to shorten the gear teeth on one of the intermeshing gears.

It is an object of this invention to provide an improved ress roll driveand to obviate the necessity or shortening the teeth on any gears forming a part of the driving mechanlsm.

It is a further important object of this invention to provide an improved differential drive for the press rolls of a paper making machine whereby the press rolls may be driven at the same or substantially -the same peripheral speed independently of any change in diameter of the lower press roll during continued use.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the" accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings: v

Figure 1 is an end elevational view of a set of presses embodying the press roll drive of my invention.

Figure 2 is a fragmentary side elevational 50 view of the same.

Jtance between the axes of the upper press roll Figure 3 is a fragmentary enlarged top plan view of the same.

Figure 4 is a sectional view taken sub stantlally on line IVIV of Figure 3.

Figure 5 is a sectional view taken substantially on line VV of Figure 4;.

Figure 6 is a fragmentary sectional view of a modified form of differential gear assembly.

The reference numeral 1 indicates one of a pair of supporting standards provided with integral arcuate shaped arms 2. A lower press roll 3 is supported from said standards 1 by means of secondary supports 4 carried .by said main supports 1'. The ends of said lower press roll re j ournaled, as at 5, in said supports 4. A rearwardly extended journal 6 carries a differential and sprocket gear assembly, indicated as a whole by the reference numeral 7, later to be described.

An upper press roll 8 is pivotally supported about a pair of stub shafts 9 that are mounted from the upper ends of the arcuate arms 2 in brackets 10. For this purpose, a pair of arms 11 are pivotally mounted intermediate their ends upon the stub shafts 9 and are provided at one of their ends with bearing brackets 12 in which the sha 1'1, 13 of said upper press roll 8 is journaled. The other ends of said arms 11 are adjustably engaged, as at 14, by mechanisms 15 carried by extensions 16 on the arcuate arms 2 for adjusting the pressure between the upper and lower press rolls.

A pinion gear 17 is secured upon the extended shaft 13 of the upper press roll 8 and meshes with a second pinion gear 18 loosely mounted upon the stub shaft 9. Since thedisshaft-13 and the stub shaft 9 is constant, the pinion gears 17 and 18 correctly mesh at all 7 times. For the same reason, it is possible to use herring-bone gears if desired.

The differential gear assembly 7 on the extended journal 6 of the lower press roll 3 comprisesa power driven, flanged member 20 rotatably positioned over the end of-the extended-journal 6 and carrying a plurality of small pinion gears 21 on peripherally spaced pins 22 extending inwardly from a flange 23 thereof. An inner pinion gear 24, keyed or otherwise securely fixed to the extended journal end 6, lies inside of the flange 23 and meshes with the pinion gears 21. An annular ear 25, loosely mounted upon the extended ournal end 6 by means of a hub 26 is provided with inwardly directed gear teeth 27 for also meshing with the teeth of the pinion gears 21.

Said annular gear 25 constitutes the follower member of the differential gear.

On the hub 26 of the annular gear 25 there is keyed or otherwise secured a sprocket gear 29. A second sprocket gear 30 is rigidly associated with the pinion gear 18 on the rear stub shaft 9 for free rotation relative to said stub shaft. A s rocket chain 31 is trained around the sproc et gears 29 and 30.

i The operation of the press roll drive of my invention is as follows: The driving .member 20 is connected to some suitable source of power, such as the standard motor drive customarily employed. Rotation of the driving member 20 acts through the small pinion gears 21 and the inner pinion gear 24 to effect rotation of the lower press roll 3. When the diameters of the two press rolls are the same,

there is no differential action, so that the annular gear 25 and attached sprocket gear 29 are rotated without independent rotation of the pinion gears 21 about the pins 22. Under these circumstances, the upper press roll 8 will be driven at the same peripheral speed as the lower press roll 3 through the sprocket gears 29 and 30, sprocket chain 31, and intermeshing pinion gears 17 and 18.

During continued use of the press rolls in paper making, however, the lower press roll, which is ordinarily rubber covered, must be grouahd down from time to time to compensate for wear and to renew the original amount of crowning that is given to the lower press roll. The result of regrinding the lower press roll is to diminish its diameter and if this were not compensated for, the peripheral speed of the lowe and upper press rolls would change. Because of their frictional contact throughout the roll surfaces, if the angular speed of rotation were maintained constant and the peripheral speeds of the two rolls were changed, with every grinding operation, this would result in unnecessary wear of the felt and, frequently, in damage to .the formation of the web passing between the two press rolls.

By the use of the differential gearing above described, the angular speed of rotation is permitted to vary with changes in the diameter of the lower press roll so as to maintain the peripheral speeds of the two press rolls substantially the same. The operation is dependent upon the well known principles of differential gearing.- In the present case, the frictional contact between t e roll-surfaces actsas a drag to keep the peripheral speeds at all times constant and this is permitted by the outer annular gear 25, or follower, so

that the upper press roll 8 will not be driven at a peripheral speed greater than that of the lower press roll 3.

It is an important feature of my invention that the idling pinion gear 18. on the stub shaft 9 and the pinion gear meshing therewith secured to the journal of the upper press roll 8 have a fixed distance between centers, independent of the changing diameter of the lower press roll 3 or of any variation in pressure between the two press rolls as effected by the adjusting mechanisms 15. There is thus no necessit for shortening the teeth on either of the pinion gears 17 orthe hub 44 of said gear 43. The operation v of this modified form of differential gear is the same as previously described but it possesses some mechanical advantages over the spur gear type. With the spur gear type of differential that has been shown there will be considerable movement at all times between .the driver and the follower part of the differential and it is also necessary to-accurately proportion the gear ratios between this differential and the top r'oll. It will be readily understood that with thespur gear type of diflerential there is a variance between the pitch diameter of the driver and follower parts, while with the bevel gear type of differential the pitch line of these two parts is the same.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.-

cured on said upper roll, a stub shaft, a differential gear assembly carried by said lower press roll including a sprocket gear associated therewith, a sprocket gear on said stub shaft, a chain connecting said sprocket gears and a gear rigidly associated with said sprocket gear on said stub shaft and meshing with said gear on said upper press roll.

2. In a paper making machine, a lower power driven press roll, an upper press roll, a stub shaft, means including a differential gear assemblyon said lower press roll, intermeshing gears on said stub shaft and upper press roll respectively and means connecting a gear on the stub shaft with the lower press roll for driving said upper press roll from said lower press roll.

3. In a paper making machine, upper and lower press rolls, a power driven differential gear through which the lower roll is driven, an idler gear, a gear secured on said upper press roll meshing with said idler gear and means driving said idler gear through said differential.

4. In a press roll assembly, upper and lower press rolls, a separately mounted idler gear, a gear carried. by said upper press roll meshing with said idler gear, a differential gear connected to said lower press roll and said idler gear and means for driving said differential gear to drive said press rolls at the same peripheral speed independently of their respective diameters.

5. In a paper making machine, upper and lower press rolls, a stub shaft, arms pivotally mounted from said stub shaft carrying said upper press roll, intermeshing gears on said stub shaft and upper press roll respectively and a power driven differential gear driving said lower press roll and driving through said intermeshing gears said upper press roll.

6. In a paper making machine, upper and lower press rolls, a stub shaft, arms pivotally mounted from said stub shaft carrying said upper press roll, intermeshing gears on said ,stub shaft and upper press roll respectively, a power driven differential gear mounted on said lower press roll for driving the same and means connecting one side of said differential gear with the gear on said stub shaft to drive said upper press roll.

7. In a press roll assembly including upper and lower press rolls, means pivotally supporting said upper press roll from a fixed axis, a power driven differential gear driving said lower roll and intermediary means in-v cluding intermeshing gears fixedly spaced relative to each other connecting said differential gear and said upper pivotally supported press roll for driving the latter.

8. In a press roll assembly including an upper and lower press roll, means pivotally supporting said upper press roll from a fixed axis, intermeshing gears centered upon said axis and the axis of said upper press roll respectively and a driven differential gear operatively connectedrto/the lower p'ress roll and to the one of said first gears on the fixed connected to said stub shaft and supporting said upper press roll, a sprocket gear and pinion gear unitarilyand looselymounted on said stub shaft, a pinion gear secured to said upper press roll and meshing with said first pinion gear, a differential gear and a sprocket gear cooperatively associated and mounted on said lower press roll, a chain connecting said sprocket gears and means for driving said differential gear to drive both press rolls at the same peripheral speed.

10. A press roll assembly comprising upper and lower press rolls and a train of gears for driving both press rolls at the same peripheral speed including a differential gear directly connected to the lower press roll and indirectly connected to the upper press roll.

11. A press roll assembly including upper and lower press rolls, stub shafts, arms pivotally mounted on said stub shafts and supporting said upper press roll, intermeshing gears on said stub shaft and upper press roll and means including a power driven differential gear driving said lower press roll and the gear mounted on saidstub shaft to rotate said press rolls at the same peripheral speed independent of a change in diameter of the lower press roll.

12. In a paper making machine, a lower press roll having an extended journal, stub shafts, an upper press roll pivotally supported from said stub shafts, a sprocket gear and pinion gear loosely mounted as a unit on one of said stub shafts, a second pinion gear secured on said upper press roll and meshing with said first pinion gear, a power driven differential gear and sprocket gear assembly mounted on said extended journal, said differential gear including an internal annular gear loose upon said extended journal and carrying said last mentioned sprocket gear secured thereto, a pinion gear secured to said journal within said annular gear, a driven member loosely mounted on said journal, small pinion gears carried by said driven member and meshing with both said inner pinion gear and annular gear and a sprocket chain trained around said sprocket gears.

In testimony whereof I have hereunto subscribed my name at Beloit, Rock County,

Wisconsin.

EARL E. BERRY. 

